(vr2, classOfVirtualReg vr2)
graph
- | otherwise
- = panic "RegAlloc.Graph.Main.graphAddCoalesce: can't coalesce two real regs"
-
+ -- We can't coalesce two real regs, but there could well be existing
+ -- hreg,hreg moves in the input code. We'll just ignore these
+ -- for coalescing purposes.
+ | RegReal _ <- r1
+ , RegReal _ <- r2
+ = graph
+
-- | Patch registers in code using the reg -> reg mapping in this graph.
patchRegsFromGraph